KR20220101706A - Pump system with clutches - Google Patents

Abstract

A pump system for a motor vehicle having a first pump 1 and a second pump 2 which can be driven by an electric motor E and/or an internal combustion engine V comprises the first pump 1 and the second pump (2) is characterized in that it can be engaged by a clutch. A method of operating a pump system in a motor vehicle comprises a first pump (1) and a second pump (2) by means of an electric motor (E) and/or an internal combustion engine (V) by combining a first pump (1) and a second pump (2). (2) driving.

Description

Pump system with clutches

The present invention relates to a pump system for a motor vehicle having a first pump and a second pump which can be driven by an electric motor and/or an internal combustion engine. The invention further relates to a method of operating a pump system in a motor vehicle and to a motor vehicle having a pump system with an internal combustion engine or electric motor.

Reduction of fuel and energy consumption in automobiles is a key focus of development in the automobile industry. In addition to the development of new technologies, the optimization of existing components is becoming increasingly important. Significant savings potential can be realized here without the enormous cost that new systems may incur. In this context, "demand-oriented auxiliary units" is the keyword.

An oil pump is one example, and is an important part of engines and transmissions. An oil pump must perform three tasks: controlling, lubricating and cooling the various hydraulic actuators. These actuators are operated from engine control. The pressure required for this must be provided by an oil pump.

In order to minimize fuel consumption and pollutant emissions, a circuit is often provided in modern drive concepts to automatically switch off the vehicle drive motor when certain conditions are met. This may be the case, for example, of a so-called gliding action when the vehicle is coasting as well as at a standstill, known as the start-stop function. If it is determined that the driver wants to continue driving or that the driver again requests drive torque from the vehicle drive motor by actuating the accelerator pedal, the vehicle drive motor is restarted without any further operational steps by the driver and the corresponding gear is shifted to the automatic transmission held or engaged, and the drive clutch is closed.

The oil pump mechanically driven by the vehicle drive motor also maintains a continuous hydraulic supply when the vehicle drive motor is stationary, or at least if required, since it does not provide any power when the motor is stationary. It is known to provide an electrically driven auxiliary oil pump that provides a corresponding oil flow at the required pressure to enable hydraulic shifting of an automatic transmission and, if applicable, the supply of additional units or components.

A method for controlling the oil supply for an automatic transmission and a starting element of a vehicle is known from DE 102005013137 A1, wherein for supplying the starting element and/or at least one hydraulic control device of the automatic transmission in the high-pressure branch and the low-pressure branch respectively At least two oil pumps are provided.

A device for controlling the actuation of the oil supply is known from DE 10162973 A1, which, in addition to a mechanical oil pump, also comprises an electric oil pump. Both oil pumps are used to supply a hydraulic control unit for operating the automatic transmission and clutch positioned between the drive motor and transmission. To have sufficient hydraulic pressure and corresponding oil mass flow available to shift the automatic transmission and clutch even when the drive motor is switched off, the electric oil pump is configured to ensure that the rotational speed of the drive engine or the associated hydraulic pressure of the mechanical oil pump is below a threshold value. When it falls, it works based on certain criteria. After the drive motor is operated again and its rotational speed exceeds the second rotational speed threshold, the electric oil pump is switched off again.

A fluid pump system for a motor vehicle with an internal combustion engine is known from US 2012/0269653 A1, in which a planetary gear is coupled to an internal combustion engine, an electric motor and a pump. Due to the interaction of the electric motor and the internal combustion engine by a common transmission, the pump operates efficiently in a given power range.

For reasons of cost, pumps of the prior art are often constant displacement pumps, ie the output is not adjustable. In order to enable demand-oriented supply by means of a pump, the pump can be configured as a variable displacement pump or a switching pump. However, these pumps have more complex constructions, incur higher costs, and often exhibit lower efficiencies.

The present invention is based on the object of providing a pump system for a motor vehicle and a method of operating a pump system in a motor vehicle, which meet the requirements for the required volumetric flow rate and pressure in an energetically advantageous manner and at low equipment costs.

According to the invention, this object is solved by a device having the features of patent claim 1 and by a method according to claim 10 . Advantageous embodiments and improvements of the invention may be found in the dependent claims. Furthermore, in claim 12 a motor vehicle with an internal combustion engine or electric motor and a pump system according to claim 1 is claimed.

The present invention is based in particular on the discovery that the required volumetric flow rate and pressure must be variable and controllable depending on the circumstances in order to reduce the energy consumption of the pumps and thus the fuel consumption or the total energy consumption of the motor vehicle. At the same time, in order to keep the construction effort low, it has been realized that it is reasonable to integrate the already known units of the pump system from the prior art into the new optimized pump system. In order to accommodate these two basic ideas, existing pumps, which often differ in their performance, must be able to be driven variably by their respective drive units and also independently of each other. This is made possible by connecting the individual components of the pump system, in particular the pumps and the drive units, by means of clutches that engage and disengage when specific needs arise.

Using this knowledge, the present invention provides a pump system for a motor vehicle, the pump system comprising: a first pump and a second pump capable of being driven by an electric motor and/or an internal combustion engine, the first pump and the second pump 2 The pump is characterized in that it can be coupled by a clutch.

The invention thus ensures that the first pump and the second pump can both be separated and thus can be driven independently of each other and can also be coupled by means of an internal combustion engine and/or an electric motor. In this way, the required volumetric flow rate and pressure are variably, individually and situationally adjusted according to the needs in the vehicle by switching the two pumps on and off. This has the advantage that only the volume flow and pressure that are actually required are provided. As a result, the pump is only driven when volumetric flow and pressure are required, and energy consumption is reduced compared to permanently driven pumps.

A further advantage is that the pump can be operated in a power range that is optimal in terms of its energy consumption. In other words, when the required volumetric flow rate and pressure correspond to the volumetric flow rate and pressure at which the pump operates efficiently in terms of energy consumption of the pump, the pump can be switched on. At the same time, it is possible to switch the pump off when the operation falls within a performance range that can be covered more efficiently by a different pump. Therefore, the energy fuel consumption of the vehicle is ultimately reduced.

Moreover, the present pump system advantageously uses pumps already used as standard in automobiles. This makes it possible to keep the construction effort and consequently the manufacturing cost of the pump system low.

Preferably, in the pump system, the internal combustion engine and the first pump may be coupled by a first clutch, the first pump and the second pump may be coupled by a second clutch, and the electric motor and the second pump may be coupled 3 It is constructed in such a way that it can be engaged by a clutch. It thus becomes possible that the first pump can be driven independently of the internal combustion engine by coupling to a second pump which is coupled to an electric motor. Conversely, the second pump can also be driven independently of the electric motor by coupling to a first pump that is coupled to the internal combustion engine. Additionally, the second pump coupled to the electric motor, the internal combustion engine and the first pump can be driven independently. This has the advantage that the pump capacity of both pumps can be used when the internal combustion engine of the motor vehicle is switched off. However, if there is not enough electrical energy available in the vehicle, the internal combustion engine can take over the drive of both pumps. Consequently, the pump system or both pumps must operate independently of the vehicle's power supply.

Moreover, when there is a high demand for volumetric flow rate and pressure, only the driving power of the internal combustion engine is required to drive both pumps, since operation in the upper power range of the pumps can be executed more efficiently by the internal combustion engine. It is advantageous if it can be used.

At the same time, when there is a low demand for volumetric flow rate and pressure, by isolating the first pump from the internal combustion engine and from the first pump, It is advantageous to drive only the second pump by the

In a still further preferred embodiment of the invention, the pump system is configured in such a way that the pressure line of the first pump and the pressure line of the second pump are connected by a connecting line. In this way, it is achieved that the pressure lines of the first pump and the second pump communicate with each other and that the volumetric flow rates can be switched alternately. This leads to the advantage that the volume flow and pressure in one pressure line can be increased by supplying the volume flow of the other line, or the target unit can be supplied with volume flow and pressure from both pumps.

In a still further preferred embodiment of the invention, the pump system comprises at least one controllable and/or non-controllable valve, in particular a flow valve, check valves, pressure valve or directional control valve, connected to the pressure lines and/or connecting lines. the way it is installed. This allows the volumetric flow rate and pressure to be controlled. In this regard, it is advantageous, for example, that fluctuations in volume flow and pressure can be mitigated.

Moreover, the volume flow rates and pressures in the pressure lines downstream of the first pump and the second pump may be adjustable in communication, or the volume flow rates in the pressure line of the first pump may be adjusted according to need in the pressure line of the second pump. , or vice versa. The advantage of this is that the volumetric flow rate can be switched as needed and in a controlled manner.

With regard to the pump system, it is further preferred that the pressure line of the first pump and the pressure line of the second pump are connected to at least one target unit, in particular to two different target units. This achieves simultaneous supply of respective volumetric flow rates and pressures to several targets. The resulting advantage is that the pump system is supplied to a plurality of consumers.

In a further preferred embodiment, the pump system is configured in such a way that the first target unit becomes a hydraulic control unit and the second target unit becomes a unit for cooling and lubricating the transmission, in particular the automatic transmission. In this way, it is possible for the transmission to be lubricated and cooled at the same time, and the hydraulic system is actuated in the hydraulic control unit by means of the pumped fluid. The advantage is that the same fluid that can be pumped through both pumps can be used, in particular an oil-based fluid.

In addition, it is preferred that the first clutch and the second clutch of the pump system are shift clutches and the third clutch is a one-way clutch, wherein the shift clutches are in particular operated mechanically, electromechanically, hydraulically or pneumatically. This allows the first pump to be variably and completely decoupled from the internal combustion engine and the second pump, where the coupling process can be carried out mechanically, electromechanically, hydraulically or pneumatically. It is advantageous if the engagement can be controlled and regulated by means of shift clutches.

It is also an advantage that the individual units can be operated independently of one another at a certain rotational speed.

In a further preferred embodiment, the pump system comprises a one-way clutch having a freewheel with respect to the direction of rotation of the shaft of the internal combustion engine. It is thus ensured that no torque from the internal combustion engine is transmitted to the electric motor when the switching clutches are closed. The resulting advantage is that the electric motor does not rotate excessively when the maximum rotational speed of the internal combustion engine is higher than that of the electric motor, which would otherwise increase energy consumption.

The use of a one-way clutch represents a lower construction effort, which in turn is further advantageous in reducing the manufacturing cost of the pump system.

It is further preferred that the pumps of the pump system are constant displacement pumps and/or variable displacement pumps and/or switching pumps, in particular flow pumps or positive displacement pumps. In constant pumps, the output is not adjustable, and their operation or performance directly depends on the operation or performance of the internal combustion engine or electric motor. However, in the present pump system, the operation of the constant displacement pumps is variable due to the separable coupling to the internal combustion engine or electric motor by the clutches. The resulting advantage is that, due to the use of constant displacement pumps, the construction effort and cost can be reduced compared to the use of variable displacement or switching pumps, and the overall efficiency can be increased.

The present invention further provides a method of operating a pump system in a motor vehicle, the method comprising driving a first pump and a second pump by means of an electric motor and/or an internal combustion engine by coupling the first pump and the second pump. includes steps.

This method thus ensures that the first pump and the second pump can both be separated and consequently driven independently of each other and can also be coupled by means of an internal combustion engine and/or an electric motor. In this way, the required volumetric flow rate and pressure are variably and individually adjusted according to the needs in the motor vehicle by switching the two pumps on and off. This has the advantage that only the volume flow and pressure that are actually required are provided. The pump is therefore only driven when volumetric flow and pressure are required, and energy consumption is reduced compared to permanently driven pumps.

A further advantage is that the pump can be operated in a power range that is optimal in terms of its energy consumption. In other words, the pump can be switched on when the required volumetric flow rate and pressure correspond to the volume flow rate and pressure at which the pump operates efficiently in terms of energy consumption of the pump. At the same time, it is possible to switch the pump off when the operation falls within a performance range that can be more effectively covered by a different pump. Therefore, the energy fuel consumption of the vehicle is ultimately reduced.

A further advantage is that the pump system uses pumps already used as standard in automobiles. This makes it possible to keep the construction effort and consequently the manufacturing cost of the pump system low.

A preferred embodiment of this method is that the internal combustion engine drives the first pump by engaging the first coupling, the electric motor drives the second pump by engaging the third clutch, or the internal combustion engine drives the first clutch and the third clutch. It is characterized in that the first pump and the second pump are driven by engaging the clutch, or the electric motor drives the first pump and the second pump by engaging the second clutch and the third clutch. It thus becomes possible that the first pump can also be driven independently of the internal combustion engine by coupling to a second pump which is coupled to an electric motor. Conversely, the second pump can also be driven independently of the electric motor by coupling to a first pump that is coupled to the internal combustion engine. Moreover, the second pump coupled to the electric motor, the internal combustion engine and the first pump can be driven independently. This has the advantage that the pump capacity of both pumps can be used when the vehicle's internal combustion engine is switched off. However, if there is not enough electrical energy available in the vehicle, the internal combustion engine can take over the drive of both pumps. Thus, the pump system or both pumps can be operated independently of the vehicle's power supply.

Moreover, only the driving power of the internal combustion engine will be used to drive both pumps, since operation in the upper power range of the pumps can be executed more efficiently by the internal combustion engine when there is a high demand for volumetric flow rate and pressure. It is advantageous to be able to

At the same time, when there is a low demand for volumetric flow rate and pressure, by separating the first pump from the internal combustion engine and from the second pump, It is advantageous to drive only the second pump by the

Additional features and advantages of devices and methods are apparent from the following description of embodiments with reference to the accompanying drawings. From these drawings it is shown:
1 is a schematic circuit diagram of a pump system;
2 is a pressure-volume flow diagram of the individual operating states of the pump system;
3 is a table of different engagement possibilities of clutches depending on the operating conditions of the pump system;
Figure 4a is a schematic circuit diagram of a pump system during a switching process of a motor vehicle;
4B is a schematic circuit diagram of a pump system during a clutch maintenance process of an automobile;
Figure 4c is a schematic circuit diagram of a pump system during cooling and lubrication of a transmission of a motor vehicle;
4D is a schematic circuit diagram of a pump system during start-stop operation of a motor vehicle;
Figure 4e is a schematic circuit diagram of a pump system during cooling and lubrication of a transmission of a motor vehicle in hybrid mode;
5A is a flow chart for operation of clutches according to operating states;
5B is a flow chart for operation of clutches according to operating states;
Fig. 5c is a flow chart for operation of clutches according to operating states;

If individual features described in different embodiments are structurally incompatible, it will be apparent to one of ordinary skill in the art that these features may also be implemented in a single embodiment. Similarly, various features that are described in the context of a single embodiment may also be provided in various embodiments individually or in any suitable subcombination. Moreover, all features mentioned above or below in relation to the method are applicable to the system and vice versa.

1 shows a schematic circuit diagram of an embodiment of the claimed pump system 100 . The pump system 100 comprises, in particular, an internal combustion engine V, also known as an internal combustion machine, configured as a main unit for driving a motor vehicle. The internal combustion engine V may be, for example, an in-line engine, a V-type engine, a VR-type engine, an H-type engine, a W-type engine, a boxer engine, a radial engine, or the like.

Moreover, according to this embodiment, an electric motor E is provided for the pump system 100 , the electric power of which is preferably lower than that of the internal combustion engine V . However, the electric motor E can also be configured such that the electric motor E can also be used as a main unit for driving a motor vehicle. For example, the electric motor E may be configured as a three-phase, linear, alternating current, direct current, general purpose, repulsion motor, or the like.

According to an embodiment, the pump system 100 comprises a first pump 1 , also referred to as a main pump, and a second pump 2 , also referred to as a secondary pump. The first pump 1 is preferably larger in dimensions than the second pump 2 . A larger dimension is understood to mean a larger output as a result of a larger stroke volume. According to the embodiment, the pumps 1 , 2 are preferably provided as constant pumps; These pumps can also be configured as variable and/or switching pumps if desired. The pumps 1 , 2 are, for example, axial, diagonal, radial, rotary, centrifugal, impeller pumps and the like. The output performance of fixed displacement pumps is in particular directly dependent on the delivered power of the drive units. That is, the delivered volume flow rate and the applied pressure are determined by the transmitted torque of the internal combustion engine (V) or electric motor (E).

In the pump system 100 of this embodiment, the internal combustion engine V and the first pump 1 are coupled by a first clutch c1. It is thus possible to transmit the torque generated by the internal combustion engine V to the pump 1 . In particular, the clutch c1 couples the shaft driven by the internal combustion engine V to another shaft driving the first pump 1 . The clutch c1 is in particular configured as a shift clutch, so that the shaft of the first pump 1 and the shaft of the internal combustion engine V can be selectively disconnected or connected. In addition, it is preferred that the clutches can be actuated, for example mechanically, electromechanically, hydraulically or pneumatically, so that they can be controlled by the control unit.

The second clutch c2 couples the first pump 1 and the second pump 2 . This clutch is also preferably provided as a shift clutch, and thus can be operated as described above, and thus can be selectively disconnected or connected. In this way, the torque applied to the first pump 1 can be transmitted to the second pump 2 . The clutch c2 engages in particular the shaft of the first pump and the shaft of the second pump 2 .

In this embodiment of the pump system, the electric motor E is coupled to the second pump 2 by a clutch c3. In particular, it is preferable that this clutch is a one-way clutch, and therefore this one-way clutch has a freewheel, particularly preferably in a direction opposite to the running direction of the electric motor E. This means that the electric motor cannot be disconnected from the second pump. It is thus possible to transmit the torque generated by the electric motor E to the pump 2 . The clutch c3 couples in particular the shaft driven by the electric motor E to another shaft driving the second pump 2 .

In the pump system 100 of the present embodiment, a tank T serving as a storage container for a fluid to be pumped, in particular an oil-based fluid, is further provided. According to the schematic circuit diagram, the tank T is connected to the suction side of the pumps 1 , 2 via a connection line.

Furthermore, the pump system 100 is configured such that a check valve 3 , 4 is installed in the pressure line 5 , 6 of the pumps 1 , 2 , which pressure line is accordingly of the pumps 1 , 2 . provided on the pressure side, thus preventing backflow of the fluid in the direction of the pumps.

According to the circuit diagram, the pump system 100 is downstream of the check valves 3 , 4 , the pressure lines 5 , 6 of the first pump 1 and the second pump 2 are connected to a connection line 7 . The hydraulic valve 8 is installed in particular at the junction between the pressure line of the second pump 2 and the pressure line of the connection line 7 , the hydraulic valve being connected via the connection line 7 . control fluid flow.

In the described embodiment, the pump system 100 is intended to supply a specific volume flow rate of fluid and a specific pressure to the first target unit 10 and the second target unit 9 . The first target unit 10 is in particular a hydraulic control unit of a transmission, in which a specific pressure is required for setting of various hydraulic actuators. Hydraulic actuators are, for example, part of transmissions of automobiles, in particular automatic transmissions. In the second target unit 9 , for example a transmission of a motor vehicle, in particular an automatic transmission, will be lubricated and cooled with the pumped fluid.

An example of a method for driving the pump system 100 in a motor vehicle is described below by way of example with reference to FIGS. 2 , 3 and 4A - 4E . For this purpose, different operating modes of the method, corresponding to selected operating states of the motor vehicle, are described.

Figure 2 is a pressure/volume flow diagram reflecting the need for a fluid volume flow rate in relation to the required pressure of the fluid in relation to different operating states of the motor vehicle; Operating states mean in particular a transmission, in particular an automatic transmission, and a driving mode of a motor vehicle. In particular, a distinction is made here between the operating states “shift”, “hold clutch” and “lubricate and cool”. Additionally, there are “start-stop” and “hybrid” operating states. These operating states can also be understood as temporal phases or processes during the operation of a motor vehicle.

The "shifting" operating state includes, inter alia, a change of gears, or in other words, a change of the speed ratio of the transmission. During this process, a pressure p1 and a volumetric flow rate V1 are required.

The "clutch hold" operating state describes, inter alia, a state in which the shift clutch must be actively operated for gear selection. During this process, a pressure p2 and a volumetric flow rate V2 are required.

The "lubricating and cooling" operating state is preferably provided during the transmission of torque via the transmission to the wheels of the motor vehicle via the drivetrain, or in other words, while power is being transmitted via the transmission. During this process, a pressure p3 and a volumetric flow rate V3 are required.

The "start-stop" operating state preferably exists when the vehicle is not moving. During this operating state, in particular the internal combustion engine V is not operating. During this process, a pressure p4 and a volumetric flow rate V4 are required.

A “hybrid” operating state is provided when the internal combustion engine V and the electric motor E are preferably operated in the motor vehicle. During this process, a pressure p5 and a volumetric flow rate V5 are required.

In particular, the following applies to the required volumetric flow rates of the embodiments described herein: V1 < V4 < V2 < V5 < V3

In particular, the following applies to the required pressure of the fluid of the embodiments described herein: p1 > p2 > p3 = p4 = p5

According to the operating states of the motor vehicle described above, FIGS. 3 and 4A - 4E show the first pump 1 driven by the drive units V, E by engaging the clutches c1, c2, c3. and the operation of the second pump 2 .

During the "switching" operating state of the motor vehicle (Fig. 4a), the volumetric flow rate V1 and the pressure p1 are required. These volumetric flow rates and pressures are supplied particularly efficiently in terms of the driving energy required for this purpose by actuating only the first pump 1 by the internal combustion engine V . In other words, due to the operation of the first pump 1 by coupling to the internal combustion engine V, the energy consumption to provide the required volumetric flow rate and pressure is lower than in all other configurations. In other words, in the required power range, the energy required to operate the pump 1 is the lowest by being coupled to the internal combustion engine V. For this purpose, the clutch c1 is engaged. However, the clutch c2 remains open and the electric motor E does not operate. During the shifting process, the oil-based fluid is transferred from the tank 1 to the hydraulic control unit 10 by a first pump 1 , as a result of which the setting of the actuators in the transmission, and thus “shifting”, is possible.

During the "clutch hold" operating state of the transmission (Fig. 4b), the volumetric flow rate V2 and pressure p2 are required. These volumetric flow rates and pressures are supplied particularly efficiently in terms of the driving energy required for this purpose by actuating the first pump 1 and the second pump 2 by means of the internal combustion engine V . For this, the clutches c1 and c2 are engaged, and the electric motor E is not operated. Due to the idle rotation of the one-way clutch c3 in the direction opposite to the rotational direction of the internal combustion engine V, no torque is applied to the electric motor E. While the clutch of the gear is maintained, the oil-based fluid is transferred from the tank 1 to the hydraulic control unit 10 and into the transmission 9 by the first pump 1 and the second pump 2 . A clutch is maintained in the vehicle's transmission, which is lubricated and cooled at the same time.

During the "lubricating and cooling" operating state of the motor vehicle (Fig. 4c), the volumetric flow rate V3 and pressure p3 are required. These volumetric flow rates and pressures are also supplied particularly efficiently in terms of the driving energy required for this purpose by actuating the first pump 1 and the second pump 2 by means of the internal combustion engine V . In other words, in the required power range, the energy required to operate the pumps 1 , 2 is the lowest as it is coupled to the internal combustion engine V . For this, the clutches c1 and c2 are engaged, and the electric motor E is not operated. Due to the idle rotation of the one-way clutch c3 in the direction opposite to the rotational direction of the internal combustion engine V, no torque is applied to the electric motor E. During this operating state of the motor vehicle, an oil-based fluid is transferred from the tank T to the hydraulic control unit 10 and into the transmission 9 by means of a first pump 1 and a second pump 2 . The transmission is lubricated and cooled.

During the "start-stop" operating state of the motor vehicle ( FIG. 4d ), the volume flow V4 and pressure p4 are required. This volumetric flow and pressure are supplied particularly efficiently in terms of the driving energy required for this purpose by actuating the second pump 2 by means of an electric motor E, in which the operation of the internal combustion engine is omitted in this operating state of the motor vehicle. because it can be During the start-stop operation of the vehicle, the clutch c3 is engaged, and the second pump 2 pumps the oil-based fluid from the tank 1 to the transmission 9 to cool the transmission 9 . Moreover, in order to further increase the volume to be transferred, it is possible to further turn on the first pump 1 by actuating the clutch c2 (not shown in Fig. 4d).

During the "hybrid" operating state of the motor vehicle (Fig. 4e), the volumetric flow rate V5 and pressure p5 are required. These volumetric flow rates and pressures are also particularly in terms of the driving energy required for this purpose by actuating the first pump 1 by means of an internal combustion engine V and the second pump 2 by means of an electric motor E. efficiently supplied. For this purpose, the clutch c1 is engaged. During this operating state of the motor vehicle, an oil-based fluid is transferred by means of a first pump 1 and a second pump 2 from the tank 1 to the hydraulic control unit 10 and into the transmission 9 for cooling and lubrication. do.

In an embodiment not shown in the figures, the pump system is configured such that only one drive unit is provided, which is an internal combustion engine V or an electric motor E. In this case, the drive unit is coupled to the first pump 1 or the second pump 2 by a variable speed clutch c1 or a one-way clutch c3. Also in this embodiment, the pumps 1 , 2 are also switched using the clutch c2 according to the principle described above, so that the pumps are operated in a particularly efficient power range with respect to the energy required.

Figures 5a, 5b and 5c show a coherent flow diagram illustrating the operation of the clutches according to the operating states described above with respect to the corresponding method parameters. The required volumetric flow rate Qreq at the individual operating states is estimated, since the pump system in this embodiment does not have corresponding sensors for determining Qreq. The parameters described in Figures 5a, 5b and 5c are abbreviated as follows:

Qreq: Volumetric flow required for operating conditions

nICE: Torque internal combustion engine

M(n)E-Mot: Electric motor torque to electric motor torque

nN: nominal rotational speed of the electric motor

nE: the current rotational speed of the electric motor

Pmax: maximum usable power of the electric motor

VP1/P2: cylinder capacity of pumps (P1, P2)

Q2E: Volume flow rate of P2 driven by electric motor: Q2(nE)

Q12E: Volume flow of P1 + P2 Q1 (nE) + Q2 (nE)

Q1ICE: Volumetric flow rate of P1 driven by internal combustion engine: Q1 (nICE)

Q12 ICE: Volume flow rate of P1 + P2 driven by internal combustion engine: Q1 (nICE) + Q2 (nICE)

ŋ: general efficiency factors

1 first pump
2 second pump
3 check valve
4 check valve
5 pressure line
6 pressure line
7 connecting line
8 hydraulic valve
9 car gearbox
10 Hydraulic control unit
100 pump system
c1 shift clutch
c2 shift clutch
c3 one-way clutch
E electric motor
T tank
V internal combustion engine

Claims (12)

A pump system for an automobile, comprising:
a first pump (1) and a second pump (2) which can be driven by an electric motor (E) and/or an internal combustion engine (V),
The first pump (1) and the second pump (2) can be coupled by a clutch (clutch),
Automotive pump systems. The method of claim 1,
The internal combustion engine V and the first pump 1 may be coupled by a first clutch c1,
The first pump 1 and the second pump 2 may be coupled by a second clutch c2, and
the electric motor (E) and the second pump (2) can be coupled by a third clutch (c3),
Automotive pump systems. 3. The method according to claim 1 or 2,
The pressure line of the first pump (1) and the pressure line of the second pump (2) are connected through a connection line,
Automotive pump systems. 4. The method according to any one of claims 1 to 3,
at least one controllable and/or non-controllable valve is installed in the pressure lines and/or connecting lines, in particular flow valves, check valves, pressure valves or directional control valves,
Automotive pump systems. 5. The method according to any one of claims 1 to 4,
the pressure line of the first pump (1) and the pressure line of the second pump (2) are connected to at least one target unit, in particular to two different target units,
Automotive pump systems. 6. The method of claim 5,
the first target unit is a hydraulic control unit and the second target unit is a unit for cooling and lubricating a transmission, in particular an automatic transmission,
Automotive pump systems. 7. The method according to any one of claims 1 to 6,
the first clutch c1 and the second clutch c2 are shifting clutches, the third clutch c3 is a one-way clutch,
wherein said shift clutches are operated in particular mechanically, electromechanically, hydraulically or pneumatically,
Automotive pump systems. 8. The method of claim 7,
the one-way clutch c3 has a freewheel with respect to the direction of rotation of the shaft of the internal combustion engine,
Automotive pump systems. 9. The method according to any one of claims 1 to 8,
wherein said pumps are constant displacement pumps and/or variable displacement pumps and/or switching pumps, in particular flow pumps or positive displacement pumps,
Automotive pump systems. A method of operating a pump system in a vehicle, comprising:
driving the first pump (1) and the second pump (2) by means of an electric motor (E) and/or an internal combustion engine (V) by coupling a first pump (1) and a second pump (2) containing,
How to operate a pump system in a car. 11. The method of claim 10,
(1) the internal combustion engine V drives the first pump 1 by engaging the first clutch c1, and the electric motor E drives the second pump 1 by engaging the third clutch c3 (2) drive; or
(2) the internal combustion engine V drives the first pump 1 and the second pump 2 by engaging the first clutch c1 and the third clutch c3, or
(3) the electric motor (E) drives the first pump (1) and the second pump (2) by engaging the second clutch (c2) and the third clutch (c3);
How to operate a pump system in a car. Having an internal combustion engine or electric motor and a pump system according to claim 1 ,
car.

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